Method and apparatus for extracting volatile constituents from carbonaceous materials



Dec. l, 1953l H. K. SAVAGE 2,561,325

METHOD AND APPARATUS FOR EXTRACTING VOLATILE CONSTITUENTS FROM CARBONCEOUS MATERIALS Filed oct. 1o, 195o 4 sheets-sheet 1 Z m F 'all FIG.

SMQ/who@ Dec. 1, 1953 2,661,325

H. K. SAVAGE METHOD AND APPARATUS FOR EXTRACTING VOLATILE CONSTITUENTS FROM CARBONACEOUS MATERIALS Filed Oct. l0, 1950 4 Sheets-Sheet 2 3o o 42 FIG. 5 45 se s2 23 35' \l/Y l/l' I i 43 42 3o I "q s 29 l' 47 A 3 www 46 HQRRY K. Sal/96E *W v Dec.. l, 1953 H. K. SAVAGE 2,661,325

METHOD AND APPARATUS FOR EXTRACTING VOLATILE: CONSTITUENTS FROM CARBONAGEOUS MATERIALS 4 Sheets-Sheet 25 Filed OGC. l0, 1950 BY MA .Ffa Z Hrm/amers.

Dec. f1, 1953 H. K. SAVAGE 2,661,325 METHOD AND APPARATUS FOR EXTRACTING VOLATILE CONSTITUENTS FROM CARBONACEOUS MATERIALS 4 Sheets-Sheet 4 Filed Oct. 10, 1950 INVENToR. HARRY A. .5m/46.5 .4Z/7:26'. 1.7. BY

#fraz/vifs.

Patented Dec. l, 1953 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR EXTRACT- ING VQLATILE vCGNSTI'1`IIEN'1`S FROM CARBONACEOUS MATERIALS Harry K. Savage, Downeye Calif. Application October 10, 1950., Serial No. 1895438v 8 Claims.

This is a continuation in part of my prior applcati-on, Serial No. 638,702, led January 2, 1945, now abandoned.

This invention relates to a method and apparatus for the recovery of volatile constituents from carbonaceous materials such as oil shales, oil sands, oil bearing diatomaceous earth, etc. This invention is particularly useful in the eX- traction of oil from shales of the character found in the State of Colorado. Oil shales of this type occur over wide areas in massive formations composed of a few beds of rich oil shale and many beds of lean shale, often outcropping as escarpments 40G feet to 500 feet high.

It is the principal object of this invention to provide an improved method and improved apparatus for the reduction of oil shales and other carbonaceous materials.

Another object of this invention is to provide an improved method and improved apparatus of this type which is exible in operation so that the time of retorting may be out to a minimum for reducing the cost of retorting, or in which the time may be extended so that higher quality products are produced. When shale oil is produced by a slow rate of retorting and distillation the yield may be low but the A. P. I. gravity of the oil is high. rIhe economic factors and the type of refining equipment available Will decide Whether the retorting operation is to be rast or slow.

The oil vapors may be fractionally condensed as they come from the retort. A large part of the hydrocarbon vapors from the retort can be condensed into products of dierent boiling ranges. This can be accomplished by passing them through a ractionating tower such as those used n conventional rening of petroleum. The products will be crude gasoline, diesel oil and heavier ends. The heavier products can be cracked in conventional refining equipment for the production of motor fuel, etc. l

From this preliminary description it is understood that the method and apparatus embodying my invention are sufficiently llexible to permit either slow or fast retorting, with the result that the gravity of oils produced may be varied through a wide range.

The principal difculty in devising a suitable method and oil shale retort for Colorado oil shale, and certain types of oil shale occurring elsewhere, has been the calring or agglomeratng characteristic when it is heated t0 retorting temperatures. Also, a suitable method of heating has been a difficult problem to solve,

Caking or agglomeration may be caused by inherent qualities inl the shale itself or by a condition of retorting. In either case, the caking canl be prevented, or broken up after it is formed, by movement of the shale in such a way that shearingA stresses will be set up within the body of oil shale as it is being retorted.

Oil shale is a poor conductor of heat which makes indirect. heating difficult. Direct heating, such as shale coming in contact with a countercurrent iiow of hot gases, presents problems, the most troublesome being the tendency of the gases to channel. The channeling can be minimized by introducing a horizontal component of flow of the shale along with the vertically downward now.

Gravity flow of the shale through the retort. isA particularly advantageous in .that internal mechanism may be omitted from the retort.

Another object of this invention is to make ecient use of the ley-product energy produced from retorting the carbonaceous materials. Thus, I propose to burn the spent carbonaceous material heating a gas and then pass the heated gas into the retort to heat additional carbonaceous material.

Another object of this invention is to cool the spent shale being discharged from the retort belovv the temperature at which it will burst into iianle when exposed to atmospheric air, in order that, .the spent` shale may be subsequently burned in a more eiiicient manner for heating gases to be used Within the retort.

Qther objects and advantages will appear hereinafter.

In the drawings:

Figure 1 is a sectional elevation showing a preferred form of apparatus as contemplated by my invention,

Figure 2 is a top view of the apparatus shown in Figure 1..

Figure 3 is a sectional plan View taken substantially on the line 3--3 as shown in Figure 1.

Figure, i is a longitudinal sectional View on an enlarged scale of. a Preferred form of valve mech arllsm employed. in connection with each of the retort outlets illustrated in Figure l.

Figure 5 `is a plan view partly in section taken subsantially on the line 5 5 as shown in Figure Figures. 6110.. are. diagrammatic views illustrat-v oovv lateral movement of the shale within the. retort, is accomplished in order .to prevent Ckng Qf.. the Shale within the. retort and in order to prevent channeling of the hot eases. Figure e 1s a side elevation. Figure 7 is a bottom plan view. Figure 8 is a plan view taken substantially on the line 8-8 as shown in Figure 6. Figure 9 is a plan view ltaken substantially on the line 9-9 as shown in Figure 6. Figure 10 is a plan View taken substantially on the line Ill-I t as shown in Figure 6.

Figure 11 is a bottom plan view in diagrammatic form showing a modified form of retort.

Figure 12 is a bottom plan view in diagrammatic form showing a further modification.

Referring to the drawings, the retort generally designated I includes a central chamber II which may be lined with a refractory I2. A steel shell I3 supports the refractory lining I2 and the floor I 4. A plurality of outlets I are uniformly spaced about the iioor I4 as shown in Figures 1 and 3. AssociatedA with each of these outlets i5 is a depending tube I5, explained more fully hereinafter. The steel skeleton on the frame I3 supports the rooi I'I and the distribution hopper i8. A conveyor diagrammatically illustrated at I9 delivers carbonaceous material to the hopper I8 at the top of the retort I0, and this material descends by gravity from the hopper into the chamber` I I by way of a plurality of feed pipes 20, for distributing the carbonaceous material within the chamber II. Near the lower end of each of the feed pipes is a lateral opening 2| communicating with a supply pipe 22 carrying a heated gas under pressure. Delivery of this hot gas into the lower end of each of the feed pipes 20 results in preheating of the carbonaceous material as it gravitates through the feed pipe 2l and also acts to prevent entrance of air from the atmosphere into the retort chamber Il.

A collector ring 23 may be provided if desired and mounted within the chamber II above the level of the outlets from the feed pipes 20. Since the space within the retort above the level of the feed pipe outlets is closed in, the use of the collector ring 23 is optional. The outlet 24 which communicates with this space within the retort may be connected to a dust separator 25 and a fractionator 26. Additional refining equipment may be of conventional character.

It has been found by experiment that that portion of the material in the chamber Il which is above a predetermined level travels downwardly as a block without cross-movement, when all of the discharge outlets are opened simultaneously. This predetermined level corresponds to a plane 28 parallel to the floor I4 and spaced above the oor a distance which may in many cases be approximately one and one-half times the spacing between the outlets I5. Below this theoretical plane appreciable coning occurs. The cone angle is steeper than the natural angle of repose because of the pressure exerted by the shale in the upper portion of the retort. The dotted lines 21 in Figure l are indicative of portions of the volume of material within the chamber II which is relatively inactive and in which no appreciable vertical movement occurs. It has been found by experiment that the height of the material above the plane 28 has very little effect on the rate of flow through the outlets I5, and therefore this height is made as great as is practicable from a standpoint of structural considerations.

While the input of carbonaceous material into the hopper I8 may be continuous, or intermittent as desired, so long as the feed pipes 20 remain full the outlets I5 normally function only intermittently. The valve mechanisms designated 25 are of a preferred type, but it is recognized that Various other valve devices may be employed within the spirit of this invention.

As shown in the drawings, the valve 2B and its associated parts include a vertical chute or Walled passage 30 depending from a vertical tube I6. The tube IB is secured to the floor I4 under each of the outlets I5. A heater element 32 is interposed between the depending tube I6 and the floor I4 and projects upwardly through an opening in the oor I4 as shown. An annular chamber 33 within the heater element 32 communicates with a supply pipe 34. A plurality of nozzle openings 35 lead from the annular chamber 33 upwardly on an angle to direct heated gas from the supply pipe 34 into the chamber II of the retort I0. A lip 36 extends inwardly above the nozzles 35 to provide protection therefor against clogging as the carbonaceous material passes through the chamber H downwardly through the openings I5 and into the depending tube 3|.

The location of the inlets for heating gases at the position of the iioor outlets is an important feature of my invention since it assures that all portions of the shale passing through the retort shall be subjected to the heat of the gases. When a particular floor outlet is open the heat introduced adjacent that outlet passes upwardly in countercurrent relation with respect to the shale descending by gravity through the outlet.

If desired. a second ring 31 may be interposed between the housing 30 and the depending tube I 6 for delivery of cooling gas on the supply pipe 38 into the lower end of the tube It. Spent shale entering the discharge openings I5 may be of a temperature about 900 F., and it may be desirable to cool this spent material to approximately 500 F. or below before discharging into the atmosphere in order to prevent the material from bursting into flame. The relatively cool gases admitted through the ports 39 in the ring 31 serve to cool the spent material within the tube I6.

A gate element 40 is pivotally mounted on the housing 30 by means of a pin 4I. The power cylinder 42 is adapted to actuate the gate element 40 by means of the piston rod e3 and connecting link 44. The power cylinder 42 is adapted to move the gate element 40 to a closed position shown in solid lines in Figure 4, or to retract it in the inoperative position shown by the dotted lines. In the inoperative position the pivoted gate forms no restriction for the passage of spent material through the passageway 45. A sealing device for the exclusion of air and retention of gases is provided at the lower end of the discharge passageway 45. As shown, this sealing device may include a disc element 46 carrying a resilient annular seal 4'.' and mounted on a ball joint 48 to move with a pivot lever 49. The pin 50 carries the lever 49 with the housing 30. A second power cylinder 5I acting through piston rod 52 is adapted to move the seal 41 into the operative position shown in solid lines to the inoperative position illustrated in dotted lines. Any convenient means such as a conveyor (not shown) may be provided for disposing of the spent material passing out through the passageway 45.

The valve devices 29 which depend from each I supply pipes 34 and 22 may be heated by combustion of the spent carbonaceous vmaterial in any conventional form of heater (not shown).

Referring to Figures 6-10', it has been found that when outlets Si, 62, 63 and 64 are opened simultaneously there are two zones of movement which are quite different from each other. The first zone comprises the entire volume of the retort down to the plane represented by the line IIJ-l0 in Figure 6. The second zone comprises the remaining portion of the retort below that horizontal plane. In the upper zone the material moves uniformly downward by block movement without substantial Vcrossflow when outlets 6|- 62-6$-64 are all open. In the lower zone the movement of the material has a horizontal component of flow as Well as a vertical component. This is caused by the tunneling of the material into smaller channels which continue to get progressively smaller until the material reaches one of the openings in the floor of the retort. The channels thus formed'by the moving material form an inverted cone, and for the oil shale rock under consideration the angle is approximately 70 with the horizontal. Throughout the distance of the funneling action the horizontal component of iiow produces shearing stresses and turbulence which increases in magnitude as the rook approaches the bottom of the retort. The level at which the funneling begins to appear is at the boundary IU-l between the upper and lower zones where the cones of flow from all four openings lil, 62, 63 and 64 become tangent to each other. This tangent relationship is shown in Figure 10. The material lying below the plane Ill-l G outside of the cones of iiow is substantially inactive.

When openings 6l, 62, 63 and 64 are allowed to flow simultaneously there is no funneling in the upper zone such as occurs in the lower zone. When opening 6l is allowed to iiow and the other openings remain closed the tunneling extends into the upper zone and to the top thereof as shown by Figure 8. All of the material hows through the funnel to the opening 6l as a horizontal component of flow, except for a very small pencil of material directly over the opening di In the lower zone particularly, the material in the pencil or center of the cone of llow moves faster than it does along the sides.

When opening 6i is closed and opening 6e is allowed to flow the material in the cone represented by 65-S-5`L Figure C, has the direction of its horizontal component of iiow changed from that which is present when only outlet Si iis open. By opening rst one outlet and then another it is clear that the direction of the horizontal component of flow of the material can be changed so that shearing stresses effectively prevent formation of objectionable large masses oi cake material, and furthermore, the channeling of heating gases is minimized. The areas rep resented by 65-61--68 and 66-61-69 in Figure 6 do not have the benefit of the change of direction of the horizontal component of flow. If, however, openings 6i, 52, 't3 and 5s are kept closed and outlet 'It is opened, the areas represented by 'l'l-lZ--lS-lll would benet from the change in direction of the horizontal component of flow. Figures 6-10 illustrate how the material within the retort may move Idownwardly under gravity with essentially block movement and yet how the individual pieces of material are caused to move laterally during the downward movement to set up shearing forces and thus to lil iil)

prevent objectionable caking of the material. This sidewise component of the motion of each of the parts of rock alsol prevents the formation of relatively xed channels. through which the hot gases would pass. The prevention of channeling insures that the materiall within the retort shall be uniformly heated. The horizontal components of flow of the shale pass transversely across the natural vertical upward iow of the heating gases.

It will be observed that the distance between centers of adjacent outlets is no greater than twice the distance between a wall of the chamber and the center of an adjacent outlet. This placement or distribution of outlets insures that descending shale pieces feeding adjacent outlets intersect within the retort chamber at a height above the iioor no greater that the height or the intersection of the cones with the chamber walls. In this way maximum ilexibility for moving shale pieces in any part of the retort longitudinally or laterally in a direction toward any particular outlet is achieved. In turn, this makes it possible to obtain maximum cross ow benelits to minimize channeling of hot gases.

In Figures 11 and 12 I have illustrated other retort shapes and other patterns of outline placement and spacing. These are illustrative only. The prime requisites for successful operation are space Within the retort substantially free of internal mechanism or other obstructions, and flexibility to manipulate the flow of shale through the outlets on the floor of the retort.

The retort shell B of Figure 11 is proportioned to conform to the three internal cones 9i which funnel to the three floor outlets 92. The height of the retort 90 is such that the cones become tangent at a level of shale within the retort corresponding to the plane i-l of Figure 7. The cones intersect above that level. At the upper end of the retort shell 9G the curved lines 93 indicate the extent of overlapping of these cones which funnel to the three outlets. In Figure l2 the retort shell l 00 is proportioned to conform to the internal cones lill which funnel to' the six door outlets m2. The height of the retort lili) is such that the outer' portions of the cones become tangent and coincident with the retort wall at the upper level of shale within the retort.

As a specic example, a retort 20 feet square and 30 feet high with one l2 inch outlet at the center of the retort floor can be emptied in approximately 1 hour of continuous ilow. This is a maximum rate of discharge, assuming the oil shale to 'be broken to a maximum size of 2 inches. The rate of subsidence in the retort is 6 inches Der minute under such conditions. Assuming an 8hour heating period, however, the shale may be withdrawn intermittently through outlets 6|-2-63-6li-l8 at -minute intervals, with the draw from all openings lasting about V8 of 25 minutes, or about 3 minutes and '7l/2 seconds. The sequence of opening of the various outlets may be varied in any desired rotation. It is not essential that only one outlet be opened at a. time; on the contrary, it is possible that the draw periods of the various outlets may overlap. It is not essential that the outlets should each be opened for the same time interval, It may be found that in retorts having a large number ci floor outlets such as,l for example, as shown in Figures 1 3, the floor outlets near the wall of the retort should handle less material than the other outlets. This compensates for the cooler zones adjacent the walls of the retort which may 7 be present because of heat losses through the retort wall.

For a given maximum size of shale fragments there is a corresponding minimum size opening through which the shale will descend by gravity. Flow of shale can be induced through smaller openings, however, by vibrating the conduit having the small opening. Accordingly, mechanical vibrators can be attached to the depending tube I6 if desired so that spent shale can be caused to move through a relatively small depending tube. Under such conditions the flow may be interrupted by stopping the vibrator.

In the use of the term sequential or in sequence as related to the opening and closing of the floor outlets of the retort, I mean only that the outlets are'opened and closed in a manner other than simultaneously.

Having fully described my invention, it is to be understood that l do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. A method of distilling volatile constituents from broken oil shale, comprising the steps of causing gravity movement of a mass of said shale through a retort and out of the retort through a plurality of longitudinally spaced and laterally spaced floor outlets, introducing hot gases into the retortl at the outlets to heat the mass of 'l shale in the retort by gases passing in a direction countercurrent to the movement of the mass of shale in the retort, and causing sequential flow of shale pieces through longitudinally spaced outlets and sequential ilow through laterally spaced outlets to change the horizontal components of the direction of flow of individual pieces of shale within the retort, and thereby minimize channeling of the hot gases.

2. A method of distilling volatile constituents from broken carbonaceous material, comprising the steps of causing gravity movement of a mass of said material through a retort and through a plurality of longitudinally and laterally spaced floor outlets in the retort, introducing hot gases into the retort adjacent the outlets to heat the broken carbonaceous material by gases passing in a direction countercurrent to the downward movement of the said material, causing sequential flow of said material through longitudinally spaced outlets and sequential flow through laterally spaced outlets, whereby localized longitudinal and lateral shifting within said material is effected as it passes through the ,retort to minimize channeling of the hot gases and to promote uniform heating of said material, and collecting the volatile constituents distilled from said material.

3. A retort for the recovery of volatile constituents from carbonaceous material, comprising a closed chamber having a substantially horizontal iioor, inlet means for the delivery of carbonaceous material into the chamber, outlet means for the discharge of spent material from the chamber including a plurality of outlets spaced longitudinally and laterally at intervals about the floor, heating means for injecting hot gases into the chamber adjacent each of said outlets, a cooling tube depending from each of said outlets, means -for injecting cooling gases into each of said cooling tubes, means associated with each of said cooling tubes for intermittently discharging a quantity of spent material by gravity, and collector means for conducting the const ituents recovered away from the retort.

4. A retort for the recovery of volatile constituents from carbonaceous material, comprising a closed chamber having a substantially horizontal floor, inlet means for the delivery of carbonaceous material into the chamber, said inlet means including a plurality of depending inlet tubes, means for injecting hot gases into each tube near its lower end for preheating the incoming carbonaceous material and for retarding ingress of atmospheric oxygen, outlet means for the discharge of spent material from the chamber including a plurality of outlets spaced longitudinally alud laterally at intervals about the oor, heating means for injecting hot gases into the chamber adjacent each of said outlets, a cooling tube depending from each of said outlets,

means associated with each of said cooling tubes for intermittently discharging a quantity of spent material by gravity, and collector means for conducting the constituents recovered away from the retort.

5. A retort for the recovery of volatile con,A

stituents from carbonaceous material, comprising a closed chamber having a substantially horizontal iloor, inlet means for the delivery of carbonaceous material into the chamber, said inlet means including a plurality of depending inlet tubes, means for injecting hot gases into each tube near its lower end for preheating the incoming carbonaceous material and for retarding ingress of atmospheric oxygen, outlet means for the discharge of spent material from the chamber including a plurality of outlets spaced longitudinally and laterally at intervals about the floor, heating means for injecting hot gases into the chamber adjacent each of said outlets, a cooling tube depending from each of said outlets, means for injecting cooling gases into each of said cooling tubes, means associated with each of said cooling tubes for intermittently discharging a quantity of spent material by gravity, and collector means for conducting the constituents recovered away from the retort.

6. A retort for the recovery of volatile constituents from carbonaceous material, comprising a closed chamber having a substantially horizontal floor, inlet means for the delivery of carbonaceous material into the chamber, outlet means for the discharge of spent material from the chamber including a plurality of outlets spaced longitudinally and laterally at intervals about the floor, heating means adjacent the door for injecting hot gases into the chamber, and means for independently opening and closing the out-` lets in any desired sequence whereby localized longitudinal and lateral shifting of the material within the chamber is eilected to minimize chanheling of said hot gases within said material.

7. Apparatus for distilling volatile constituents from broken oil shale, comprising in combination: a retort having an interior space substantially free of obstructions and provided with a plurality of longitudinally and laterally spaced oor outlets, inlet means for the delivery of broken oil shale into the upper portion of the retort, means for introducing hot gases into the retort at the outlets to heat the shale in the retort by gases passing in a direction countercurrent to the movement of the shale in the retort, means for independently opening and closing the longitudinally spaced and laterally spaced iioor outlets to eect localized longitudinal and lateral shifting of the shale particles as the mass of shale passes through the retort to minimize channeling of said hot gases Within the mass of shale, and collector means for conducting the constituents recovered away from the retort.

8. A retort for the recovery of volatile constituents from broken carbonaceous material, comprising: walls forming a closed chamber having a substantially horizontal oor, inlet means for the delivery of 'broken carbonaceous material into the chamber for gravity ow therethrough, outlet means for the discharge oi spent material from the chamber including a plurality of outlets spaced longitudinally and laterally at intervals about the floor, the distance between centers of adjacent outlets being no greater than twice the distance between a Wall of the chamber and the center of an adjacent outlet, whereby the cones of descending broken carbonaceous material feeding adjacent outlets intersect within the chamber at a height above the oor no greater than the height of the intersection of the said cones with the chamber walls, means for injecting hot gases into the chamber adjacent each of said outlets, and means for independently opening and closing the outlets in any desired sequence whereby localized longitudinal and lateral shifting of said material may be effected to minimize channeling of said hot gases within said material.

HARRY K. SAVAGE.

References Cited in the le Of this patent UNITED STATES PATENTS Number Name Date 825,536 Hills July 10, 1906 1,818,567 McIntire Aug. 11, 1931 1,901,169 Karrich Mar. 14, 1933 2,072,392 West Mar. 2, 19-37 

8. A RETORT FOR THE RECOVERY OF VOLATILE CONSTITUENTS FROM BROKEN CARBONACEOUS MATERIAL, COMPRISING: WALLS FORMING A CLOSED CHAMBER HAVING A SUBSTANTIALLY HORIZONTAL FLOOR, INLET MEANS FOR THE DELIVERY OF BROKEN CARBONACEOUS MATERIAL INTO THE CHAMBER FOR GRAVITY FLOW THERETHROUGH, OUTLET MEANS FOR THE DISCHARGE OF SPENT MATERIAL FROM THE CHAMBER INCLUDING A PLURALITY OF OUTLETS SPACED LONGITUDINALLY AND LATERALLY AT INTERVALS ABOUT THE FLOOR, THE DISTANCE BETWEEN CENTERS OF ADJACENT OUTLETS BEING NO GREATER THAN TWICE THE DISTANCE BETWEEN A WALL OF THE CHAMBER AND THE CENTER OF AN ADJACENT OUTLET, WHEREBY THE CONES OF DESCENDING BROKEN CARBONACEOUS MATERIAL FEEDING ADJACENT OUTLETS INTERSECT WITH- 